It sounds pretty final to me too. That's what I thought when I first heard it. There might be some weird deluxe version of this game but it would be a little sad if there is nothing more to come. Although I have to admit that the game has come a long way since its inception.
I understand that "Grandmaster Edition" sounds rather definitive but there will always be room for improvement as well as new features. I mean, what the heck, people are still buying CM 9000 and both that version and CM 10 are available at my local Best Buy store.
The only issue, I think, is how well the new version does in terms of sales. In that regard, it's probably not going to be an easy sell for the uninitiated, novice, and/or misinformed considering it's $39.99 when CM 10 is half that price and CM 9000 is only 10 bucks.
Bottom line is you can almost bet the farm there will be another version down the road if CM XI (Grandmaster) sells anywhere near as many copies as CM 10 and CM 9000.